Q: I upgraded my MacBook to Yosemite a while back.  It now runs quite slowly.  I see I have Photos as well as iPhoto - does that mean I have 2 libraries of photos?  And can I safely delete the old one?

No, you do not have two libraries, and you do not want to delete anything. Photos uses the same Library that iPhoto does.

Cheers,

GB

Regarding the slowness of your Macbook download and run Etrecheck.  Copy and paste the results into your reply. Etrecheck is a diagnostic tool that was developed by one of the most respected users here (and recommended by Apple Support personnel) in the ASC to help identify the more obvious culprits that can adversely affect a Mac's performance.

You can delete the old iPhoto library as long as you're sure you want to stay with the new Photos.  The two libraries don't take up twice the space on the hard drive as described in this Apple document: Photos saves disk space by sharing images with your iPhoto or Aperture libraries - Apple Support so there's very little space to be regained by deleting it.

Photos is new and currently is missing a lot of iPhoto's features and capabilities.  You might want to keep both libraries working until you're sure Photos will do what you want it to do. This user tip describes the differences between the two apps: Photos 2.0 vs iPhoto 9.6.1:  Features and Capabilities

Tell Apple what missing features you'd like restored or new features added in Photos via  Apple-Photos Feedback.

The feedback is working as can be seen from the following paragraph in this Apple webpage: Apple OS X El Capitan.

Photos has been fine-tuned to make it even easier to manage your library. Now you can add a location to a single image or to an entire Moment. Naming your favorite people in Faces is faster with a streamlined workflow. You can also sort your albums — and the contents inside them — by date, title, and more.

Most welcome, Ginger!

GB

gail from maine wrote:

 

No, you do not have two libraries, and you do not want to delete anything. Photos uses the same Library that iPhoto does.

 

Cheers,

 

GB

This is not correct

Photos uses Hard Links to link to the iPhoto library - the two libraries are totally separate and either can be deleted without affecting the other one - however it is critical not to think they are the same  - because they are different libraries changes made to one are not made to the other

Photos saves disk space by sharing images with your iPhoto or Aperture libraries - Apple Support

However as noted in the article

After you migrate your iPhoto or Aperture library to Photos, you might feel tempted to delete your original iPhoto or Aperture library. Because the migrated library takes little additional space, you don't need to delete the original library.

I would suggest keeping both for a minimum of three months to be sure you do not need the iphoto library - and I plan to keep both for longer than that - probably forever

LN

Thanks for the clarification LarryHN! My misunderstanding!

GB

You are welcome

LN

You are welcome

Thanks for helping people here

LN

GB

Thank you, Old Toad, for pointing us to the Apple Photos feedback area.

The Etrecheck report can't fix anything. It's only a diagnostic tool.  If you post the report here we can take a look at it for any obvious items that could affect performance.